A Queens firefighter – whose image was captured in the now-famous photo of a U.S. flag being raised over the rubble where the World Trade Center once stood – was a hero to a 4-year-old Kentucky boy five years before the Sept. 11 terror attacks.

Firefighter George Johnson, 36, came to the rescue in 1996 when the family of Forrest Nichols, who lives in Mundfordville, Ky., was desperately searching for a way to save his life following a bout with leukemia.

“He gave me bone marrow,” Forrest said. “He’s the only one that had my blood. He saved my life.”

Forrest needed a bone-marrow transplant – his only chance of surviving the disease after three years of unsuccessful chemotherapy treatments.

When no one in his family matched his marrow type, the boy’s parents, Stacy and Michael Nichols, enrolled Forrest in the National Marrow Donor Program Registry in the hopes of finding a donor.

That’s when Johnson’s generosity came to the rescue.

Johnson, the firefighter standing at the left in the Ground Zero photograph and currently stationed at Ladder 157 in Brooklyn, was identified as a match.

Johnson – along with firefighters Danny McWilliams and Billy Eisengrein – had spent six hours searching when they were ordered to evacuate when 7 World Trade Center was on the verge of collapse.

That’s when the trio planted an American flag atop a mountain of debris and twisted rubble – much like the servicemen at Iwo Jima did in World War II.